Induction
The Life Cycle
of a Feather
Mesenchymal
Condensation
Anterior-
Posterior
Asymmetry
Proximal-
Distal
Elongation
Follicle
Invagination
Barb and
Barbule
Formation
Differentiation
Regeneration
feather filament
barb plate
Placode
Short bud
Long bud
Marginal plate
Follicle
Lin et a.,
2006. Molecular signaling
in feather morphogenesis.
Curr Opin Cell Biol. 18:730-741.